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pythonargparse

Don't parse options after the last positional argument

I'm writing a wrapper around the ssh command line client. After the first positional argument that's part of command, all further options should also be treated as positional arguments.

Under optparse, I believe this would be done with disable_interspersed_args.

Presently I have something like this:

parser = argparse.ArgumentParser()
parser.add_argument('--parallel', default=False, action='store_true')
# maybe allow no command? this would ssh interactively into each machine...
parser.add_argument('command', nargs='+')
args = parser.parse_args()

But if options are passed as part of the command (such as my_wrapper ls -l), they're instead interpreted by ArgumentParser as unknown options. error: unrecognized arguments: -l

If I use parse_known_args(), the options may be taken out of order. 

p = argparse.ArgumentParser()
p.add_argument('-a', action='store_true')
p.add_argument('command', nargs='+')
print(p.parse_known_args())

$ python3 bah.py -b ls -l -a
(Namespace(a=True, command=['ls']), ['-b', '-l'])

Here you can see that -b's position before ls has been lost, and -a has been parsed out from the command, which is not desired.

How can I:

  • Prevent arguments from being parsed after a certain point?
  • Disable parsing of interspersed arguments?
  • Allow arguments with a prefix to be consumed as positional arguments?
Solution

  • I had the same problem. I found the solution on the argparse bug tracker: http://code.google.com/p/argparse/issues/detail?id=52

    The solution is simple: replace nargs='+' (or '*') with nargs=argparse.REMAINDER. This special value is not documented, but it does what you want.